Pollutant Concentrations

Air quality readings will be available hourly from 7am to 11pm. Air quality readings from 12am to 6am will be made available at 7am on the same day.

Readings on 15 Jan 2015

View reading for:

Region

24-hr Sulphur dioxide(µg/m3)

24-hr PM10(µg/m3)

1-hr Nitrogen dioxide(µg/m3)a

8-hr Ozone(µg/m3)

8-hr Carbon monoxide(mg/m3)

24-hr PM2.5(µg/m3)

North

7(4)

25(25)

21(-)

27(11)

0.4(4)

11(47)

South

10(6)

25(25)

7(-)

29(12)

0.4(4)

10(42)

East

8(5)

27(27)

11(-)

47(20)

0.4(4)

15(55)

West

2(1)

28(28)

10(-)

48(20)

0.4(4)

10(43)

Central

4(2)

22(22)

21(-)

45(19)

0.3(3)

7(29)

1-hr PM2.5 (µg/m3)b Readings on 15 Jan 2015

View reading for:

Time

1am

2am

3am

4am

5am

6am

7am

8am

9am

10am

11am

12pm

North

8

10

15

16

13

12

10

7

18

12

11

15

South

7

5

6

6

8

4

7

5

7

12

23

20

East

19

16

20

25

15

22

20

15

14

23

13

18

West

14

9

9

7

7

12

10

4

9

9

20

13

Central

5

7

2

6

2

4

3

3

8

7

11

9

Time

1pm

2pm

3pm

4pm

5pm

6pm

7pm

8pm

9pm

10pm

11pm

12am

North

11

11

10

9

10

8

8

10

7

17

13

-

South

14

21

14

12

20

8

12

9

7

7

7

-

East

17

9

8

11

10

12

12

16

8

16

14

-

West

20

11

12

8

7

12

8

10

9

10

11

-

Central

9

6

9

8

11

8

12

8

8

11

5

-

Note:a Sub-index for nitrogen dioxide is reported only when the 1-hr concentration equals or exceeds 1130 µg/m3.

b There is no sub-index for 1-hr PM2.5.

3-hr PSI Readings from 1am to 12am on
15 Jan 2015

Time

1am

2am

3am

4am

5am

6am

7am

8am

9am

10am

11am

12pm

3-hr PSI

37

37

42

44

44

44

41

38

39

43

52

54

Time

1pm

2pm

3pm

4pm

5pm

6pm

7pm

8pm

9pm

10pm

11pm

12am

3-hr PSI

54

53

50

44

45

43

44

42

40

43

42

-

Hourly updates of 3-hr PSI readings are provided from 7am to 11pm. The 3-hr PSI readings from 12am to 6am will be made available at 7am on the same day. The 3-hr PSI readings are calculated based on PM2.5 concentrations only.